class_docstr: Unit tests for the gradient function
docstr: Test that the grad function agrees with autograd
docstr_tok: ["Test","that","the","grad","function","agrees","with","autograd"]
code: def test_agrees_with_autograd(self, tol):
      """Test that the grad function agrees with autograd"""
  
      def cost(x):
          return np.sum(np.sin(x) * x[0] ** 3)
  
      grad_fn = qml.grad(cost)
      params = np.array([0.5, 1.0, 2.0], requires_grad=True)
      res = grad_fn(params)
      expected = autograd.grad(cost)(params)
  
      assert np.allclose(res, expected, atol=tol, rtol=0)
  
imports: import autograd
  import pytest
  import pennylane
  from pennylane import numpy
label_desc: Use image node_id 2 for calling the TestGrad obj's underlying member method code with example usage: obj.test_agrees_with_autograd(tol) and returns: np